It could be its centredness?
For in this one I really like the clear division in two halves by the horizon and the centre-placement of the rain area, I like the bit of land from the left and the way how the whole image seems to open up from the left to the right, with less and less clouds and most light on the right. There are some dynamics in that composition that contradict the relative serenity that is inherent in centred compositions, and that creates a kind of tension that I really like!